Chemistry CCEA AS Level 1.7 (Redox)

What is a redox reaction?

One where oxidation and reduction both occur

What is oxidation?

- Loss of electrons

- Increase in oxidation number

- Gain of oxygen

What is reduction?

- Gain of electrons

- Decrease in oxidation number

- Loss of oxygen

What is the oxidation number of an uncombined element?

0

What is the oxidation number of oxygen in a compound?

-2

What is the oxidation number of hydrogen in a compound?

+1

When is oxygen's oxidation number -1?

Peroxides (such as H2O2)

When is hydrogen's oxidation number -1?

Metal hydrides

What happens to an oxidising agent in a reaction?

It is reduced

What happens to a reducing agent in a reaction?

It is oxidised

What is a disproportionation reaction?

A reaction where oxidation and reduction happen to the same element in the same reaction